Insincere Voting on the Security Council

UNSC resolutions make it easier to gather support for war. Thus, the United States seeks Security Council approval when it looks to initiate a conflict.

Resolutions also limit the scope of interventions.

Thus, states that do not like resolutions might not veto them if they expect an intervention to take place anyway. It is better to allow a UNSC-constrained intervention than an unconstrained intervention.